Tightener for conveyer belts



Jan. 30, 1962 G. M. GREENBERGER 3,018,875

TIGHTENER FOR coNvEYER BELTS Filed April 12, 1960 30 11W/Ewan. 34126 eof'e 7% wenef'geff BY 32 @yn/ Afro/mers United States Patent() 1 3,018,875 TIGHTENER FR CONVEYER BELTS George M. Greenberger, 90 Hallam Road, Buffalo 16, N.Y. Filed Apr. 12, 1960, Ser. No. 21,743 8 Claims. (Cl. 198-208) This invention relates to a belt tightener and more particularly to tighteners for conveyer belts moved over the deck of a sheet metal box, wood or roller bed, or other support having vertical sides to which the body part or casting of the belt -tightener is bolted or otherwise secured, the adjustable parts of the belt tightener supporting the end bearings of the end or return roller of the conveyer in such manner that this roller can be moved toward and from the end of the sheet metal boX or body to adjust the tightness of the belt.

The principal object of the invention is to reduce the number of parts of the belt tightener to a minimum and still achieve a secure mounting for the head and tail pulleys complete with their roller bearings in all positions of adjustment; a powerful yet highly accurate screw adjustment; protection of the screw from accidental mutilation; compactness; andtrim appearance.

Another object is to avoid the necessity for the provision of lefts and rights for parts at opposite sides of the conveyer, the parts being fully interchangeable and useable without modification on either side.

'Another object is to provide sucha belt tightener the I parts of which require little machining and which at the same time is smooth and non-erratic in its adjusting movement.

Another aim is to provide a form of the invention in which the principal parts are arranged inside of the sheet metal box which forms the deck rather than the outside thereof.

Other objects and advantages of the invention will be apparent from the following description and drawings in which:

FIG. 1 is a side elevational view of a belt Yconveyer having takeups embodying the present invention.

FIG. 2 is a vertical section taken generally along line 2 2, FIG. 1, through the conveyer belt and showing the rest of the parts in elevation.

FIG. 3 is an enlarged fragmentary side elevational view similar to FIG. 1 and showing the end of the conveyer in greater detail.

FIG. 4 is a fragmentary generally horizontal section taken on line 4 4, FIG. 3.

FIG. 5 is a fragmentary vertical section taken generally on line 5 5, FIG. 3.

FIG. 6 is a fragmentary vertical section taken generally on line 6 6, FIG. 3.

FIG. 7 is a view similar to FIG. 6 illustrating a modified form of the invention.

While the invention is applicable for use as a takeup for the belt of any type of conveyer, it is particularly illustrated in conjunction with a horizontal conveyer having one or more sheet metal boxes indicated generally at 10. This box has an upper deck 11 frorn which vertical side anges 12 project downwardly and these side anges have their lower ends continued in the form of short inwardly projecting strengthening anges 13. This box can be supported at any elevation or at any inclination, as by legs 15 connected to the bottom lianges 13 at suitable intervals.

The belt 16 travels along the upper surface of the deck 11 and is driven by a drive roller (not shown) at one end of this deck. At the opposite end of the deck this belt travels around the end return roller 18 and thence upwardly over one of a series of tracking rollers 19 arranged within the box 10. Each of these tracking rollers 70 19 is shown as having end stub shafts 20 journalled in bearings 21, suitably mounted on the opposing faces of 3,018,8'i5 Patented Jan. 30, 1962 ICS 2 the vertical side flanges 12 and the purpose of these tracking rollers is to support the inoperative or return stretch of the belt 16 inside the box 10 or to guide it in any other desired direction.

To hold the upper operative stretch of the belt 16 in centered relation to the deck 11, the end return roller 18 is preferably of enlarged diameter at its center and is provided with diminishing tapers toward its opposite ends from which stub shafts 22 project. The present invention is concerned with the provision of an adjustable bearing for each of these stub shafts whereby the return yroller 18 can be adjusted lengthwise of and toward and from the end of the box 10 thereby to adjust the tightness of the belt 16.

The belt tighteners at opposite side of the return roller 18 are identical in construction, and in fact the parts are interchangeable without the necessity of providing rights and lefts. Accordingly a description of the belt tightener at one side of the conveyer will be deemed to apply to the belt tightener at the opposite side of the conveyer'.

Each belt tightener includes a body in the form of a metal casting indicated generally at 25. This casting is of generally rectangular form in elevation and is substantially equal in height to the height of the side flanges 12 j ofthe box 10. Each of these castings is secured to the corresponding side ange 12 near the return roller 18V erably the nuts 28 for these bolts are tightened against the outside of the casting 25 so as to be readily accessible.

At one end each casting is formed to provide an integral horizontally outwardly and laterally projecting boss which forms a nut 29V for an adjusting screw 30. This adjusting screw is arranged lengthwise of the casting 25 centrally along its outer face and is provided with an outof-round head 31 at its end remote from the return roller 18 and by means of which the screw s turned to adjust the tightness of the belt.

A feature of the invention resides in the protection of each adjusting screw 30 against accidental injury and to this end the cating 25 is provided with upper and lower horizontally outwardly projecting edge flanges 32. These flanges preferably project outwardly beyond at least the threaded shank of this adjusting belt so as to embrace the same and protect the threads thereof from accidental mutilation. A conventional lock nut 33 tightened against the nut or boss 29 is provided for holding the screw 30 in its adiusted position.

A feature of the invention resides in the provision of a longitudinal groove or recess 34 cast in the face of the casting 25 opposing the side flange 12 of the box 10 and extending from one end thereof to the other. This groove rectangular form in cross section to provide in conjunction with the side ange 12 to which the casting is attached a A guideway enclosed on all four sides and open at its opposite ends. the straight tongue 35 of a bearing holder indicated generally at 36. This bearing holder is in the form of a at plate and to support the bearing the outboard end of the tongue 35 is in the form of an enlargement 38. This enlarged outboard portion of the bearing holder is provided centrally with a large opening 39 through which the adjacent stub shaft 22 extends as best shown in FIG. 4. The end of each stub shaft 22 is journalled in a bearing 40 secured to the outside face of the enlargement 33 in any suitable manner as by the four corner bolts,41 shown. The invention is not concerned with the details of the bearings 40 and any suitable form of bearings can j This guideway snugly receives and guides 0. ment plate indicated generally 21;,42. against Whiclteach, screw 30 bears in providing the desired tightness of the belt. This abutment plate is preferably in the form of a single piece of sheet metal having aV rectangular base or body portion. 43 conforming to the base portion of the bearing 40. and interpo:ed-between each bearingand enlarged portion 38 of the corresponding bearing holder'v 36 and secured by the same bolts 41` which pass therethrough. The base portion 43 of the abutment plate 42 projects beyond the end of each bearing 40 on the side of the screw 30 and is formed to provide an outwardly projecting flange 44 which is preferably perpendicular to the base portion 43V and is preferably reinforced by a diagonal extending return bend 45 at its outboardencLvthis return bend bearing against the base portion '43. This base portion 43 is, of course, provided with a hole 46 in register with the hole 39 and through which the corresponding stubshaft 22 extends.

In the adjustment` ofthe form of the invention shown in FIGS. 1-6, when itis desired to, say, tighten the belt 16, the lock nuts 33 at opposite sides of the conveyer are backed offand the adjusting screws 30 turned, by means of4 their heads 31, to effect the desired tightening of the belt; Thus, as each screw 30 is moved in the direction to tighten the belt itforces againstand moves the flange 44 of the corresponding abutment plate 42l thereby to eX- tend the bearing holder 36 and the return roller 18 jour.. nalledtherein. In this movement the tongue 35 off this bearing holder 36 slides along the slideway jointly provided by the U-shaped groove-34falongthe inner face of the, casting 25 and the opposing outer face of the adjacent, side flange 12 ofthe box 10. After the desiredfadjusteach side ofthe conveyer ment of the belt tightener athas beenachieved, thelock nuts 33 are tightened toV hold this adjustment.

It will particularly benoted that the onepiece or integral casting 25 serves a number of functions. Thus, it serves as amounting for the integral, nut 29 which carries the adjusting screw 30. In addition, its flanges 32 project beyond the shank and'protect the threads of this adjustingA screw. In addition,r this onepiece casting provides the greater part of the guideway for the tongue 35 oftheV bearing holder, the remaining part of this guideway being provided by side flange 12- of the box 10 to which this casting is secured. Itwill also be noted that the abutment 42 against which each screw 3l) works is in the form ofv a very simple sheet metal plate having, in effect, two simple bends and which at the same time provides a sturdy and reliable seat for the end of the` adjustingI screwy 30.

It will also be particularly notedthat the casting 25; bearing holders 36; abutment plates 42; and all'other parts, such as the bearings-40 are directly interchangeable atropposite sides of the conveyer` so that it is unnecessary tovprovide these inY-` rights and lefts thei fact that the casting direction so that in, say, the conveyerto the other upside down. Also,vw hile the bearing support.36,is.not vertically symmetrical, it plate so that in, say, transferring it to the opposite side ofthe conveyer no inversion is necessary.

The formof the invention shown in FIG. 7fis essentially designed to place the belt tightener inside the box instead-of` outside as shown in FIGS. 1 6. The construction ofthe parts is the same as with the preferred construction exceptthat since the adjusting screw is adequately protected there is no necessity for the provision of edge flanges 32 as with the form of the invention shown in-FIGS. 1-6. Since in other respects the form of beltl tightener. shown in FIG. 7 is substantially identical with the` form shown in FIGS. 1 6, the same. reference. nu-

merals have been applied and distinguished by thesuflx` a and the description of the manipulation of: the belt.-

iiglltener. willnotberrneatei This is dueto` 25 is symmetrical in a verticalchanging itV from one sideoff all-,that is required is to.turn.it.

is in the form of asimple flatV From the,4 foregoing twi1lbeseen that the, present in vention provides a belt tightener of simplified construction which is low in cost and at the same time of sturdy reliable and compact construction and accomplishes the various objectsiset forth.

I claim:

1. A beltl tightener for a belt travelling over the deck of a sheet metal box having upright side flanges at the opposite edges of said deck and the end of the belt passingaround a.y roller arranged beyond one end of the box with its axis generally parallel with s aid deck and journalledin bearings at its opposite ends, comprising a single metal body member fixed to a vertical side face of each off said vertical flanges at said o ne end of said box and having" a externalv groove in its face opposing and enclosedbythe vertical flange and opening at its end toward` said rollerl whereby said groove in said body and vertical side face of said flange jointly provide a laterally enclosed slideway, a bearing holder having an outboard end4 fixedv to a corresponding one of saidv bearings and having` af tongue slidingly fitted in said slideway, a nut fixed to the face of said body opposite that containing said externalA grooveon an axis directed toward the adjacent oner of saidbearings, a screw in said nut, and an abutment member interposed between the end of each screw and the corresponding bearing.`

2. Arbelt tightenerl as setforth v-in.c1aim 1 wherein said body withits-groove and said nuty arein the, form of a onepieceV integral casting.l

`3. A belt tightener as set forth .in claim 2 wherein said body is provided with laterallyV projecting integralflanges and arrangedgenerally parallel with and embracing said screw.

4. A belt tightener as set forth in claim 2 wherein the longitudinalpaxisof saidnutand' groove are centrally disposed with reference to said body sothat said body can be usedinterchangeably oneither s ide of the box.

5. A belt tightener as set forth in claim 2 wherein said groove; is ofy substantally rectangular form in cross section.

6. A belt tightener as set forth in claim 5 wherein said bearing-holderisinV theform ofay flat plate with itstongue of cross sectionalform to snuglyflt said groove and with its, outboard end enlarged.

7. Ak.belt tightener as set forth/in claim 6 wherein said abutment member is in the form of a plate interposer between each bearing and the-enlarged outboard end of each. bearing holder and having a transverse flange arranged perpendicular to and opposing the end of said screw.

8. A belt tightener for a belt travelling over the deck of, aisheetV metal boxihaving upright side flanges at the opposite edges of said deck and the endy of the belt passing around a roller arrangedbeyond oneendY of` the box with its axis generally parallel withsaid'deck and journalled in ,bearings-at'ts. opposite ends, comprising a metal body member fixed to one vertialjside face of each of said,vertical,flanges.atsaid` one-end `of, said box, a nut fxredto the'outerl face o f said bodyon-lan axis directed towardthe adjacentonelofsaidbearings, a screw-Y in said nut, abearing holden slidinglygsupported'on said body for'movement lengthwise of said screw, means securing each bearing against one face of the outboard end of each bearing holder,`a sheet-:metalplate clamped between each bearing` and said one face of each bearing holder, and

anV integral laterallyvprojecting flange on each sheet metall platearranged perpendicularly to; andopposing the end of. said screw.

References Cited` in the file of thispatenty UNITED ,STATES PATENTS- 

